This invention relates to heatsinks and packaging of integrated circuit chips.
Due to significant power dissipation in integrated circuit (IC) chips, such as chip scale package (CSP) power devices, it is often necessary to attach an external heatsink in order to keep the device junction temperature below its rated value. However, in CSP devices, the bare die is exposed to the environment. Therefore, special care must be taken to avoid excessive pressure when a heatsink is attached, in order to avoid damaging the die.
Descriptions of various prior art heatsink packages can be found in the following patents: U.S. Pat. No. 5,367,193, entitled “Low cost, thermally efficient, and surface mountable semiconductor package for a high applied power VLSI die”, U.S. Pat No. 5,789,810, entitled “Semiconductor cap”, U.S. Pat. No. 5,905,636, entitled “Heat dissipation apparatus and method for attaching a heat dissipation apparatus to an electronic device”, U.S. Pat. No. 5,909,057, entitled “Integrated heat spreader/stiffener with apertures for semiconductor package”, U.S. Pat. No. 6,069,023, entitled “Attaching heat sinks directly to flip chips and ceramic chip carriers”, U.S. Pat. No. 6,175,500, entitled “Surface mount thermal connections”, and U.S. Pat. No. 6,255,140, entitled “Flip Chip Chip-Scale Package”.